Background playback · iPhone & iPad
Keep the music playing
with the screen off.
What has to be true for audio to survive a locked phone, which buttons the lock screen actually gets, and how to make it stop on its own.
The sleep timer is part of Pro. Free to use. Pro is one payment — forever.
- Screen offthe audio keeps going
- Skip · Scrubwired to the lock screen
- 8-second fadewhen the sleep timer ends
Screen off, app in the background, app closed — three different things
Most confusion about background playback comes from treating these as one situation.
- The screen is off. Side button, or auto-lock. The app is still running and the audio is untouched. If music stops here, something is wrong.
- The app is in the background. Messages, or the home screen. Fine, provided the app was built to keep going.
- The app was swiped out of the app switcher. A hard stop, in every app on the phone, and no setting changes it.
What separates the middle case from silence is plumbing: the app must declare that it makes sound off screen, and hold an active audio session in the category that means “this app is the music”. Miss either and the audio cuts the moment the app leaves the screen.
Y2K Player declares audio as its only background capability, and sets that category at launch. The session switches on at the first press of play — activating it is a blocking round trip to the audio server, and doing it at launch costs seconds of splash screen.
The lock screen is drawn by iOS, from what the app hands it
The app does not draw that card, and cannot decide what its buttons look like.
An app publishes two things: a dictionary describing what is playing — title, artist, artwork, length, position — and a list of the commands it will accept. iOS builds the card from the first and picks the buttons from the second.
That second list is why a podcast app and a music app look different on the same lock screen: register skip-interval commands and you get fifteen-second arrows, register track commands and you get skip buttons, register neither and you get a bare play button.
It is also why the same buttons work on a Bluetooth speaker, on headphones, and on a steering wheel — they send the identical commands the lock screen sends.
Exactly what is wired up, and what is not
- Play, pause, and toggle. The third is what a headphone button sends when it does not know your state.
- Next track and previous track. Previous behaves the way you expect: past three seconds into a song it restarts that song, before three seconds it goes back a track.
- Scrubbing. Dragging the progress bar seeks the song, converted back into real file time before it moves.
- Title and artist, from the file’s own tags.
- Artwork, in three fallbacks: the picture embedded in the file, decoded down to 1024 pixels so a 3000-pixel sleeve never sits in memory whole; then a cover you set yourself; then a dark tile with the app’s mark.
- No fifteen-second arrows. The track commands are registered instead, so you get skip buttons.
- No speed control out there. From the lock screen you change what is playing, not how it sounds.
- No CarPlay. Audio reaches a car over Bluetooth or a cable like any other sound, and wheel controls work because they send the same commands — but there is no in-dash interface.
- The visualizer stops. Its renderer pauses when the app is off screen. The audio chain does not: tempo, pitch and effects are still applied to every sample.
How to do it on an iPhone
There is nothing to switch on. The point of the list is knowing what to check when it does not work.
- Add music you ownTap Add and pick audio files from Files or a share sheet. They copy in, so they play offline.
- Press play, then lock the phoneNothing to switch on. The audio keeps running; only the screen goes dark.
- Raise the lock screenCover art, title, artist and a progress bar. If that card is missing, the app is not publishing now-playing info.
- Skip and scrub from thereSkip buttons move through the queue, and each song arrives at its own saved speed.
- Set it to stop, if you are sleepingOpen the actions sheet on the player and pick a length, or End of this song.
The clock problem that only shows up when you change the speed
If you slow songs down, this detail decides whether the lock screen is useful or actively misleading.
The progress bar is not a picture of the file. It is two numbers the app publishes — the length, and how far in you are. An app at normal speed publishes the file’s own duration and is right. One playing a 4:00 song at half speed cannot — that takes eight minutes, and a bar reading 4:00 hits the end while the music is halfway through.
Y2K Player publishes stretched time. A 4:00 song at 50% reads as 8:00, and the bar fills at the rate the music is actually moving. Drag it and the position comes back in stretched seconds, so the app multiplies it out to a real position in the file before seeking.
Because that clock is already stretched, the rate published alongside it is 1.0, which keeps the bar crawling correctly instead of at double time. Move the tempo slider while the card is up and it refreshes a third of a second after your finger stops.
Why music stops when you did not stop it
Four causes, in roughly the order they happen to people.
Something else took the audio. A call, Siri, an alarm. iOS hands the audio over and tells the app it was interrupted. The right behaviour is to pause, then resume only if the system says resuming is appropriate. Guessing here is what makes music restart by itself in your pocket.
Headphones came out. Pulling a cable or a Bluetooth device dropping is a route change, and an app that ignores it sends the music to the phone’s speaker at whatever volume was set. The convention is to pause instead, and this app pauses.
The output changed underneath it. AirPods moving from an iPad to a phone, a car stereo joining, a sample rate changing. This is the quiet one: the audio engine stops itself, with no error, and a silent background app gets suspended and eventually terminated — which is what people mean by an app that “reset itself overnight”. Y2K Player watches for that change, keeps the position, rebuilds the chain and carries on from the same second.
You closed the app. Nothing to fix. Swiping it away ends playback everywhere.
Making it stop on its own after you fall asleep
The phone locking itself does nothing, so something else has to decide when the music ends.
There are two general answers on an iPhone. The Clock app has a timer whose end sound can be set to stop playing instead of ringing — blunt, but it stops any app. The other is a timer inside the player, which knows what it is stopping and can be gentler.
Y2K Player’s is the second kind. Fifteen, thirty, forty-five, sixty or ninety minutes, or End of this song — the option most people actually want at bedtime, because it lets the track finish instead of cutting off mid-chorus. When a minute timer runs out, the volume comes down over eight seconds on an ease-out curve and playback pauses, rather than stopping dead.
The timer is session-only: closing the app cancels it, which is right for something you set at bedtime. It is a Pro feature; background playback and the lock screen are not.
Long files help too: anything fifteen minutes or longer remembers where you left off.
Put a song on and lock the phone
Background playback, the lock screen card, skipping and scrubbing are all free. No account, no connection.
Questions about playing with the screen off
Answered here rather than after you install anything.
Does music keep playing when the iPhone screen turns off?
Yes, in any app built for it. Locking the phone does not touch the audio — it turns off the display. What decides whether a particular app survives is whether it declared background audio and holds an active playback session. Y2K Player does both, and audio is the only thing it keeps running in the background.
Why does my music stop when I lock my phone?
Almost always one of four things: another app or a call took the audio session, headphones or a Bluetooth device dropped, the output route changed underneath the app, or the app was swiped out of the app switcher. The first three are handled deliberately here — pause, pause, and rebuild from the same position. The fourth is a hard stop on every iPhone.
Can I skip songs from the lock screen?
Yes. Next track and previous track are both registered, so the lock screen shows skip buttons. Previous restarts the current song if you are more than three seconds in and goes back a track if you are not.
Can I scrub or jump forward fifteen seconds?
You can scrub: dragging the progress bar seeks the song. There are no fifteen-second arrows, because iOS shows either the skip-interval buttons or the track buttons and this app registers the track ones.
Why does the lock screen show a different length than the song?
Because the song is playing at a different speed. If the app published the file’s own duration while playing at 50%, the bar would reach the end when the music was halfway through. Y2K Player publishes stretched time instead — a 4:00 song at 50% reads 8:00 — and converts your scrub position back to real file time before it seeks.
How do I make music stop after I fall asleep?
Two ways on an iPhone. The Clock app’s timer can be set to stop playing instead of ringing, which stops whatever is making sound in any app. Or use a timer inside the player: in Y2K Player that is 15, 30, 45, 60 or 90 minutes, or End of this song, with an eight-second fade before it pauses. The sleep timer is part of Pro.
Does the sleep timer work with the screen off?
Yes. The app stays awake for as long as it is making sound, so the timer runs normally with the phone locked. It is tied to the app being alive, though — closing the app cancels it, which is deliberate for something set at bedtime.
Does it work in the car?
Over Bluetooth or a cable, yes, and the play, pause and skip controls on a steering wheel work because they send the same commands the lock screen does. There is no CarPlay screen for this app.
Why did the music stop when my AirPods switched devices?
Switching an audio route out from under a running engine makes the engine stop itself, silently, and a silent background app is eventually suspended and killed. That is the usual cause of an app that seems to have reset overnight. Y2K Player watches for the change, keeps the position, rebuilds the audio chain and continues from the same second.
Does the speed I set carry over when I skip from the lock screen?
Each song carries its own saved tempo, pitch and effects, and loads them when it starts. Skipping forward from the lock screen brings up the next song at its own settings rather than the previous one’s.
Does background playback drain the battery?
Audio in the background is cheap next to a lit screen, which is why listening with the phone locked costs less than watching it play. When the app is off screen the visualizer’s renderer pauses and the analysis feeding it switches off, and Low Power Mode drops the time-stretch quality to its cheaper setting without interrupting the song.
Does any of this need an internet connection or an account?
No. Files you add are copied into the app, so playback, the lock screen controls and the sleep timer all work in airplane mode. There is no account.
Does background playback cost anything?
No. Playing with the screen off, the lock screen card, skipping and scrubbing are all in the free app. Free to use. Pro is one payment — forever. The sleep timer is one of the things Pro adds.
Where to go next
Press play, then put the phone in your pocket.
Background playback and every lock screen control are in the free app, and none of it needs a connection.
Free to download and keep. Pro is a one-time purchase — buy it once and it never renews.